summaryrefslogtreecommitdiffstats
path: root/drivers/net/mdio/mdio-mscc-miim.c
blob: 2d67e12c8262aa0edfc39848a831ac09c1f19f28 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
 * Driver for the MDIO interface of Microsemi network switches.
 *
 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
 * Copyright (c) 2017 Microsemi Corporation
 */

#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>

#define MSCC_MIIM_REG_STATUS		0x0
#define		MSCC_MIIM_STATUS_STAT_PENDING	BIT(2)
#define		MSCC_MIIM_STATUS_STAT_BUSY	BIT(3)
#define MSCC_MIIM_REG_CMD		0x8
#define		MSCC_MIIM_CMD_OPR_WRITE		BIT(1)
#define		MSCC_MIIM_CMD_OPR_READ		BIT(2)
#define		MSCC_MIIM_CMD_WRDATA_SHIFT	4
#define		MSCC_MIIM_CMD_REGAD_SHIFT	20
#define		MSCC_MIIM_CMD_PHYAD_SHIFT	25
#define		MSCC_MIIM_CMD_VLD		BIT(31)
#define MSCC_MIIM_REG_DATA		0xC
#define		MSCC_MIIM_DATA_ERROR		(BIT(16) | BIT(17))

#define MSCC_PHY_REG_PHY_CFG	0x0
#define		PHY_CFG_PHY_ENA		(BIT(0) | BIT(1) | BIT(2) | BIT(3))
#define		PHY_CFG_PHY_COMMON_RESET BIT(4)
#define		PHY_CFG_PHY_RESET	(BIT(5) | BIT(6) | BIT(7) | BIT(8))
#define MSCC_PHY_REG_PHY_STATUS	0x4

struct mscc_miim_dev {
	void __iomem *regs;
	void __iomem *phy_regs;
};

/* When high resolution timers aren't built-in: we can't use usleep_range() as
 * we would sleep way too long. Use udelay() instead.
 */
#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us)	\
({									\
	if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS))			\
		readl_poll_timeout_atomic(addr, val, cond, delay_us,	\
					  timeout_us);			\
	readl_poll_timeout(addr, val, cond, delay_us, timeout_us);	\
})

static int mscc_miim_wait_ready(struct mii_bus *bus)
{
	struct mscc_miim_dev *miim = bus->priv;
	u32 val;

	return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
				       !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50,
				       10000);
}

static int mscc_miim_wait_pending(struct mii_bus *bus)
{
	struct mscc_miim_dev *miim = bus->priv;
	u32 val;

	return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
				       !(val & MSCC_MIIM_STATUS_STAT_PENDING),
				       50, 10000);
}

static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
{
	struct mscc_miim_dev *miim = bus->priv;
	u32 val;
	int ret;

	ret = mscc_miim_wait_pending(bus);
	if (ret)
		goto out;

	writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
	       (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ,
	       miim->regs + MSCC_MIIM_REG_CMD);

	ret = mscc_miim_wait_ready(bus);
	if (ret)
		goto out;

	val = readl(miim->regs + MSCC_MIIM_REG_DATA);
	if (val & MSCC_MIIM_DATA_ERROR) {
		ret = -EIO;
		goto out;
	}

	ret = val & 0xFFFF;
out:
	return ret;
}

static int mscc_miim_write(struct mii_bus *bus, int mii_id,
			   int regnum, u16 value)
{
	struct mscc_miim_dev *miim = bus->priv;
	int ret;

	ret = mscc_miim_wait_pending(bus);
	if (ret < 0)
		goto out;

	writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
	       (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
	       (value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
	       MSCC_MIIM_CMD_OPR_WRITE,
	       miim->regs + MSCC_MIIM_REG_CMD);

out:
	return ret;
}

static int mscc_miim_reset(struct mii_bus *bus)
{
	struct mscc_miim_dev *miim = bus->priv;

	if (miim->phy_regs) {
		writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
		writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
		mdelay(500);
	}

	return 0;
}

static int mscc_miim_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct mii_bus *bus;
	struct mscc_miim_dev *dev;
	int ret;

	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev));
	if (!bus)
		return -ENOMEM;

	bus->name = "mscc_miim";
	bus->read = mscc_miim_read;
	bus->write = mscc_miim_write;
	bus->reset = mscc_miim_reset;
	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
	bus->parent = &pdev->dev;

	dev = bus->priv;
	dev->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
	if (IS_ERR(dev->regs)) {
		dev_err(&pdev->dev, "Unable to map MIIM registers\n");
		return PTR_ERR(dev->regs);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
	if (res) {
		dev->phy_regs = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(dev->phy_regs)) {
			dev_err(&pdev->dev, "Unable to map internal phy registers\n");
			return PTR_ERR(dev->phy_regs);
		}
	}

	ret = of_mdiobus_register(bus, pdev->dev.of_node);
	if (ret < 0) {
		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, bus);

	return 0;
}

static int mscc_miim_remove(struct platform_device *pdev)
{
	struct mii_bus *bus = platform_get_drvdata(pdev);

	mdiobus_unregister(bus);

	return 0;
}

static const struct of_device_id mscc_miim_match[] = {
	{ .compatible = "mscc,ocelot-miim" },
	{ }
};
MODULE_DEVICE_TABLE(of, mscc_miim_match);

static struct platform_driver mscc_miim_driver = {
	.probe = mscc_miim_probe,
	.remove = mscc_miim_remove,
	.driver = {
		.name = "mscc-miim",
		.of_match_table = mscc_miim_match,
	},
};

module_platform_driver(mscc_miim_driver);

MODULE_DESCRIPTION("Microsemi MIIM driver");
MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
MODULE_LICENSE("Dual MIT/GPL");